The invention relates to an injection syringe as well as a disposal container for receiving injection needle units after their use on such injection syringe.
The injection syringe disclosed in EP 0 787 501 A2 is the starting point for the present invention; it comprises essentially the following elements:                a housing for receiving a medicament ampule provided with a sealing member;        a plunger movable in the longitudinal direction of the housing for pushing the sealing member into the medicament ampule;        a holder for an injection needle unit, wherein the injection needle unit comprises a hub-shaped cannula support detachably insertable into the holder and having at its rearward end a radially outwardly oriented flange ring into which a cannula is inserted so as to project to the front and to the rear;        a spreading sleeve with elastic spreading tongues that have at their forward end radially inwardly oriented noses which, when the injection needle unit is inserted into the holder, engage behind the flange ring of the cannula support, as well as also radially oriented spreading projections and are mounted with their rearward ends on a cylinder ring fastened on the syringe housing; and        a sliding sleeve movable to the rear against the force of a spring, wherein the sliding sleeve is designed such that, when it is moved to the rear, it is pushed against the spreading projections so that in this way the spreading tongues are pushed radially outwardly for releasing the injection needle unit.        
In this known injection syringe the spreading member has three spreading tongues provided at their rearward ends facing the cylinder ring with spreading projections that are radially inwardly oriented. The sliding sleeve is provided with radially outwardly oriented projections which upon movement of the sliding sleeve in the direction of the syringe housing press against the spreading projections provided on the spreading tongues so that the spreading tongues all together are moved outwardly and release in this way the injection needle unit.
The spreading projections provided at the rearward ends of the spreading tongues as well as the sliding sleeve provided with the outwardly oriented projections cause an increased expenditure that also makes manufacture more difficult, aside from the fact that only three spreading tongues cannot always ensure a safe insertion and fixation of the injection needle unit in the holding device.